#include <bits/stdc++.h>
using namespace std;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
using Int = long long;
const char newl = '\n';

//INSERT ABOVE HERE
const Int MAX = 1e5+100;
const Int INF = 1e18;
Int dp[4][MAX];

Int cnt[4][100]={};

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  for(Int i=0;i<4;i++)
    for(Int j=0;j<MAX;j++)
      dp[i][j]=INF;

  Int n,k;
  cin>>n>>k;

  vector<string> ss(n);
  vector<Int> cs(n);
  for(Int i=0;i<n;i++) cin>>ss[i]>>cs[i];

  string B="JOI$";
  for(Int i=0;i<3;i++)
    for(Int p=0;p<n;p++)
      for(char c:ss[p])
        if(c==B[i]) cnt[i][p]++;

  dp[0][0]=0;
  for(Int i=0;i<3;i++){
    for(Int j=0;j<k;j++){
      for(Int p=0;p<n;p++){
        if(j+cnt[i][p]<k){
          chmin(dp[i][j+cnt[i][p]],dp[i][j]+cs[p]);
        }else{
          Int need=k-j,start=0;
          for(char c:ss[p]){
            if(c==B[i]) need--;
            if(need<=0 and c==B[i+1]) start++;
          }
          if(need>0){
            cout<<j<<" "<<k<<endl;
            cout<<cnt[i][p]<<endl;
            cout<<B[i]<<' '<<ss[p]<<endl;
          }
          assert(need<=0);
          chmin(dp[i+1][start],dp[i][j]+cs[p]);
        }
      }
    }
  }

  Int ans=dp[3][0];
  if(ans==INF) ans=-1;
  cout<<ans<<newl;
  return 0;
}